Threaded fastener

Abstract

Various embodiments provide a fastener including a head, a shank connected to the head and having a tip, one or more helical thread formations extending outwardly from the shank, and wherein a bottom portion of the head includes a plurality of ribs that extend towards the tip of the shank and that are shaped to abruptly frictionally engage a surface of a first object being attached to a second object to create an immediate frictional torsional resistance of a desired force level to the tightening of the fastener. This frictional resistance is provided back to the tightening tool to inform the operator of the tightening tool that the head of the fastener has sufficiently engaged the first object and that further tightening or clockwise rotation of the fastener is unnecessary.

The invention is claimed as follows: 
     
         1 . A fastener comprising:
 a shank having a first end and a second end opposite the first end, the second end including a tip, the shank having a first longitudinal axis extending from the first end to the second end;   a helical thread formation integrally connected to and extending outwardly from the shank, wherein the helical thread formation is configured such that: (a) when the fastener is rotated in a substrate in a first direction, the helical thread formation causes the tightening of the fastener in the substrate, and (b) when the fastener is rotated in the substrate in an opposite second direction, the helical thread formation causes the loosening of the fastener in the substrate; and   a head integrally connected to the first end of the shank, the head including a top portion and a bottom portion, the top portion defining an engaging structure engageable by a tool, the bottom portion including a plurality of ribs, wherein each rib is inwardly tapered and includes:
 a multi-part leading face including a first leading surface and a second leading surface that extends transversely from first leading surface, 
 a multi-part trailing face that meets the multi-part leading face at a multi-part leading edge, the multi-part trailing face including a first trailing surface and a second trailing surface that extends transversely from first trailing surface, and 
 the multi-part leading edge including an apex at an outermost end point of the multi-part leading edge. 
   
     
     
         2 . The fastener of  claim 1 , wherein each of the ribs extends to the shank. 
     
     
         3 . The fastener of  claim 1 , wherein each of the ribs are identically sized and shaped. 
     
     
         4 . The fastener of  claim 1 , which only includes four ribs. 
     
     
         5 . The fastener of  claim 1 , which only includes five ribs. 
     
     
         6 . The fastener of  claim 1 , which only includes six ribs. 
     
     
         7 . The fastener of  claim 1 , wherein for each rib, the second leading surface extends at an obtuse angle to the first leading surface. 
     
     
         8 . The fastener of  claim 7 , wherein for each rib, the second trailing surface extends at an obtuse angle to the first trailing surface. 
     
     
         9 . The fastener of  claim 1 , wherein for each rib, the second trailing surface extends at an obtuse angle to the first trailing surface. 
     
     
         10 . A fastener comprising:
 a shank having a first end and a second end opposite the first end, the second end including a tip, the shank having a first longitudinal axis extending from the first end to the second end;   helical thread formation integrally connected to and extending outwardly from the shank, wherein the helical thread formation is configured such that: (a) when the fastener is rotated in a substrate in a first direction, the helical thread formation causes the tightening of the fastener in the substrate, and (b) when the fastener is rotated in the substrate in an opposite second direction, the helical thread formation causes the loosening of the fastener in the substrate; and   a head integrally connected to the first end of the shank, the head including a top portion and a bottom portion, the top portion defining an engaging structure engageable by a tool, the bottom portion including only four, only five, or only six ribs, wherein each rib includes:
 a multi-part leading face including a first leading surface and a second leading surface that extends transversely from first leading surface, 
 a multi-part trailing face that meets the multi-part leading face at a multi-part leading edge, the multi-part trailing face including a first trailing surface and a second trailing surface that extends transversely from first trailing surface, and 
 the multi-part leading edge including an apex at an outermost end point of the multi-part leading edge. 
   
     
     
         11 . The fastener of  claim 10 , wherein each rib extends to the shank. 
     
     
         12 . The fastener of  claim 10 , wherein each rib is inwardly tapered. 
     
     
         13 . The fastener of  claim 10 , wherein the ribs are identically sized and shaped. 
     
     
         14 . The fastener of  claim 10 , wherein for each rib, the second leading surface extends at an obtuse angle to the first leading surface. 
     
     
         15 . The fastener of  claim 14 , wherein for each rib, the second trailing surface extends at an obtuse angle to the first trailing surface. 
     
     
         16 . The fastener of  claim 10 , wherein for each rib, the second trailing surface extends at an obtuse angle to the first trailing surface.